Pool makes me think tropical, so how about some palms? Needle palm, Rhapidophyllum hystrix, is one of the hardiest palms out there. Then, how about some hardy hibiscus, along with some cannas. Elephant ears are probably marginally hardy where you are but would do great in pots that you could overwinter in a garage or basement. Russian cypress (Microbiata decussata) has lacy evergreen foliage that would make it a great edging plant around a pool.

Douglas,
thank you very much! I am going to head to the nursery to start looking at some of your suggestions this weekend. It gets me back into an excited state of mind thinking that this "hole in the ground" can actually be exciting as a landscape feature in our yard.
I really appreciate the suggestions!!!